Garbage Disposal Not Working? Here's How to Figure Out What's Wrong

Start Here: The Reset Button

Get a flashlight and look at the bottom of the disposal unit under the sink. There is a small button, usually red, sticking out from the center or slightly off-center. That is the thermal overload reset button.

When the disposal jams or overheats, it trips this button to protect the motor. The button pops out about a quarter inch and the disposal goes completely dead. Pressing it back in restores power. That is it.

About half the "disposal is dead" calls Ryan gets are this. The homeowner has had a completely functional disposal for a week, just with the reset button tripped. Press it in firmly until you feel it click, then try the switch. If it hums or runs, you are done.

If It Hums but Does Not Spin: Use the Hex Wrench

A disposal that hums when you flip the switch but does not grind is jammed, not dead. The motor is getting power, but the grinding plate is stuck. Running it in this state for more than a few seconds will trip the reset button again or burn out the motor.

Turn the switch off. Look at the very center of the bottom of the unit. There is a hex socket there, usually 1/4 inch. Most disposals ship with a small hex wrench specifically for this purpose. If you do not have it, a standard 1/4-inch hex key from any hardware store works fine.

Insert the key and crank it back and forth. You are manually turning the grinding plate to break whatever is jamming it loose. Work it both directions. Once it moves freely, remove the key, turn the disposal back on briefly to see if the obstruction clears, and then reset if needed.

A caller a few months back had ground up a small piece of a broken coffee mug. The ceramic wedged the plate solid. Five minutes with the hex key and the disposal ran fine.

If Nothing Happens at All

Complete silence when you flip the switch means either no power is reaching the unit or the reset button is tripped. Go in this order:

1. Check the reset button first. Press it in and try the switch.
2. Check the circuit breaker. Disposals are on a dedicated circuit in most homes built after the mid-1980s. Find the panel, look for a tripped breaker labeled "disposal" or "kitchen appliance," and reset it.
3. If the breaker is fine and the reset button is in and it still does nothing, the motor is dead.

A disposal with a dead motor is almost always worth replacing rather than repairing. Motor replacements cost nearly as much as a new unit.

Leaks: Location Tells You Everything

Where a disposal leaks tells you exactly what is wrong and whether it is a repair or a replacement.

Leak from the top, where the drain basket meets the sink: The sink flange has failed. The plumber's putty around the basket has dried out or the mounting hardware has loosened. This is repairable: clean the old putty, reapply fresh putty, reseat the flange, and tighten the mounting ring. Worth doing on a younger unit. On an older one, factor in the age.

Leak from the side, where the dishwasher drain hose connects: The clamp or the rubber fitting where the dishwasher drain enters the disposal has failed. Usually a clamp tightening or a replacement fitting fixes it. Inexpensive repair.

Leak from the drain outlet on the bottom side of the unit: The internal seal between the motor and the grinding chamber has failed. This is an internal failure. At this point, replace the unit. The repair cost approaches or exceeds what a new disposal costs.

Leak from the bottom center of the unit, not from a fitting: The shell of the unit itself is cracked or a seal has completely failed. Replace it.

When to Replace Instead of Repair

Age is the biggest factor. Garbage disposals have a working life of about 8 to 12 years with normal use. After that, the grinding components wear down, the motor runs louder, and repairs become a cycle of small fixes rather than a lasting solution.

Replace if any of these apply:

• The unit is more than 10 years old and has had more than one failure.
• The grinding plate is visibly worn smooth. You can check this with a flashlight into the top of the unit. If the grinding surface looks flat rather than ridged or textured, it is worn out.
• It leaks at the mounting flange and has leaked before. A repeated flange leak on an older unit usually means the body of the unit is warped or corroded at the top ring.
• It runs louder than it used to and makes a metallic grinding sound even with no food in it. That is bearing wear.

If a repair is going to cost more than half the price of a new unit on an older disposal, replacement is the better investment. Call for a free estimate.

Brands Worth Buying, Brands to Skip

InSinkErator has been the industry standard for decades for a reason. Their badger line is the workhorse entry-level unit; their Evolution series handles heavier use and is noticeably quieter. Parts are available, the units are well-supported, and they last. Moen disposals are also well-built and come with a solid warranty. Both are appropriate choices for a residential kitchen.

The cheap generic disposals sold online, often under unfamiliar brand names, tend to fail early and have limited parts availability. It is not worth saving a small amount now on a unit that will need replacing in three years.

Why Installation Details Matter

A disposal that drains poorly or backs up into the dishwasher is usually an installation problem, not a unit problem. Two things matter here:

First, the dishwasher drain connection. The disposal has a knockout plug on the inlet port for the dishwasher drain hose. If a dishwasher is connected, that plug needs to be removed before installation. If it is not, the dishwasher cannot drain into the disposal. This sounds basic, but it gets missed.

Second, the P-trap configuration. The disposal drain outlet connects to the P-trap under the sink, which connects to the drain line in the wall. The outlet needs to be above the trap entry point and the drain line needs to slope correctly toward the wall. A flat or reverse-sloped drain line causes water to sit in the line and back up. This is the usual cause of a disposal that drains slowly or smells sour.

An air gap, which is the small chrome fitting you sometimes see on the counter beside the faucet, prevents drain water from siphoning back into the dishwasher. Some areas require it by code; others do not. If your dishwasher has drainage problems, check whether an air gap is installed and functioning.